Reference
Chromatography Column Glossary: Key Terms for Process Buyers
The vocabulary that comes up when you spec an industrial chromatography column, defined in plain language.
5 min read · Updated June 12, 2026
Bed volume (BV)
The volume of packed media inside the column. It sets capacity and is the reference unit for flow rates and buffer volumes (e.g., “5 BV wash”).
Bed height
The packed height of the media. Taller beds improve resolution but raise back-pressure; chosen from the resin's recommended range.
Inner diameter (ID)
The internal width of the column tube. With bed height it determines bed volume; with flow rate it determines linear velocity.
Linear velocity
Flow rate divided by the column's cross-sectional area (cm/h). It must stay within the resin's pressure-flow limits for good performance.
HETP
Height Equivalent to a Theoretical Plate — a measure of column efficiency from a tracer test. Lower HETP means a sharper, better-packed bed.
Slurry fill
Packing method where media is suspended in buffer and flowed into the column so it settles evenly, then compressed to the target bed height.
Hydraulic control unit (HCU)
The system that drives the column adapter to pack, compress, and operate the bed — mechanical (manual) or digital (PLC-driven, recipe-based).
ASME-coded
Built and stamped to the ASME Boiler and Pressure Vessel Code, certifying the vessel's pressure integrity through qualified design, welds, and inspection.
IQ/OQ
Installation Qualification and Operational Qualification — documented evidence that equipment is installed correctly and operates as intended, required in GMP.
CIP / SIP
Clean-in-Place and Steam-in-Place — cleaning and sterilization performed without disassembly. Hygienic column design supports both.
316L stainless steel
The standard low-carbon stainless for process columns: holds pressure, electropolishes well, and resists standard buffers and CIP chemistries.
C-22 Hastelloy
A nickel-chromium-molybdenum alloy with superior corrosion resistance, used when chemistries are too aggressive (high chloride, low pH) for stainless.
Electropolishing
An electrochemical finish that smooths the metal surface to reduce product hold-up and improve cleanability — standard for GMP hygienic design.
Dynamic binding capacity (DBC)
How much target molecule a resin can capture per unit volume under flow. It drives how much bed volume a given batch requires.
USP Class VI
A USP biocompatibility classification for polymeric materials. Class VI materials can be specified where product-contact plastics must meet it.
Want the longer reads? See sizing a column, choosing a material, and slurry-fill packing.
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